Descendants of a Louisiana plantation owner rallied to his defense, insisting that the Oscar-nominated movie “12 Years a Slave” unfairly portrayed him as a tyrant.

The critically acclaimed movie – based on the book by former slave Solomon Northrup – cast William Prince Ford as a loathsome hypocrite who preached the word of God while allowing his field overseers to brutalize slaves.

“By all accounts, my great-great-grandfather treated his slaves well and did his best for them,” Ford’s 77-year-old great-great grandson William Marcus Ford told The Mail on Sunday newspaper.

“He was born at a particular time in history when slavery was accepted throughout the South. It wasn’t illegal. That doesn’t make it right or moral by today’s standards but back then it wasn’t an ethical issue. [Slave and “12 Years” writer Solomon] Northup saw him as a kindly person. He was a highly moral man.”

There could be a morsel of truth in in Ford’s protest.

In one passage of “12 years,” Northrup wrote of Ford, “there never was a more kind, noble, candid, Christian man than William Ford.”

Louisiana historian Frank Eakin said it’s entirely possible Ford was, by 19th century standards, more humane than other slave owners — but not due to humanitarian concerns.

Many plantation owners of the time were still shaken by the 1831 uprising of Virginia slave Nat Turner, who led a rebellion that killed dozens of Southern whites.

Eakin said he believes Ford was a “benevolent” master, in hopes of keeping the peace.

“Compared to some sadistic masters, Ford was relatively benevolent but this was part of a strategy that he devised to try to preserve the slave system’s status quo,” Eakin said.

“There was tremendous fear because of the purported murder plot and there also was a growing problem of slaves absconding.”

Eakin added: “Violence had worked in the past as a means of control but now the worry for slave owners like Ford was that if you were violent to a slave, he might kill you.”

Anne Marie Ford Barrios said she believes her great-great-great-grandfather was a kind man — and pawned off any additional cruelty suffered by Northrup and other servants to Ford’s wife Martha Ford.

The wife and her brother Robert were known to have regularly terrorized field hands.

“William Ford married into that,” said Barrios, 46.

And even if Barrios has some beefs with “12 Years,” she’s still a fan of the Oscar-nominated work.

“Slavery was America’s greatest shame,” said Barrios, a space shuttle engineer. “On the whole, I think the film is great in that it gets the story out there.”